Facebook: Check if User liked Facebook Fanpage Tab - php

Question

I know, that my question was asked a lot of times here, but for me no answer worked.
I've created a Facebook Fanpage Tab. All the files are stored at my private Webspace.
Now I want to determine if a user already liked the page or haven't liked it yet!
So I used this code:
<?php
function parsePageSignedRequest() {
if (isset($_REQUEST['signed_request'])) {
$encoded_sig = null;
$payload = null;
list($encoded_sig, $payload) = explode('.', $_REQUEST['signed_request'], 2);
$sig = base64_decode(strtr($encoded_sig, '-_', '+/'));
$data = json_decode(base64_decode(strtr($payload, '-_', '+/'), true));
return $data;
}
return false;
}
if($signed_request == parsePageSignedRequest()) {
if($signed_request->page->liked) {
$isteinfan = "false";
}
else {
$isteinfan = "true";
}
}
//PHP Variable an JavaScript übergeben
echo "<script>";
echo "isteinfan = '$isteinfan';";
echo "console.log('ist ein fan: ');";
echo "console.log(isteinfan);";
echo "</script>";
?>
But it doesn't work.
Can u give me help, please!!!
Yours, Raphael

Answer 1

I would recommend you include the facebook php library, which you can download from https://github.com/facebook/php-sdk/tree/master/src. You have to place all the three files in the same directory. Then you can get the liked status very easily:
define('APP_ID','xxxxxxxx');
define('APP_SECRET','xxxxxxxx');
require ("facebook.php");
$facebook = new Facebook(array(
'appId' => APP_ID,
'secret' => APP_SECRET,
'cookie' => true,
));
$signed_request = $facebook->getSignedRequest();
$liked = $signed_request["page"]["liked"];
Now $liked is a boolean which can be true or false